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Re: MANDRAGORA OFFICINARUM

BJ:

The answer is that stratification does not equal "freezing", and two 
processes are confused: 1) destruction of inhibitors at low temperatures, 
at which point germination may proceed over a wide range of temperatures 
but most rapidly at warmer temperature.  This equates with the most 
common sense of stratification, and the original sense of the term.

2) Some species [and this is particularly common in mild, winter-rain 
climates like coastal California] germinate better, or only, at low 
temperatures.  But, as one would expect, above-freezing temperatures.

Many of west-coast natives fit the second category.  The best examples 
would be native Iris, eg, I.innominata, douglasiana, tenax; and 
Erythronium.  These and many others need to germinate after the winter 
rains arrive, and well before warmer temperatures arrive.  It's not 
surprising that they have low temperature optima for germination.  On the 
other hand, most native annuals "don't care" -- they don't need to 
develop storage organs for the summer drought, so they germinate well in 
either high or low temperatures.

Hope this makes sense for the Sisyrinchium story.

Loren Russell, Corvallis, Oregon
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